Emmetropia is a state of vision where a viewer sees objects clearly at both near and far distances. The cornea and crystalline lens collectively focus the light entering the eye to the central regions of the retina. Emmetropia is achieved when the collective refractive powers of the cornea and crystalline lens focus light exactly onto the central portion of the retina.
Myopia is a vision condition where objects near to a viewer appear clear, but objects that are spaced farther away from the viewer get progressively blurred. Myopia is sometimes referred to as being nearsighted. Myopia can be caused by any number of conditions and reasons. A significant factor for many cases of myopia includes an elongated axial length of the eye. Myopia occurs when the focal point of the focused light entering the eye is formed before the retina. In other words, the focus of the light rays entering the eye converges short of the retina.
Another condition that is affected by the eye's axial length is hyperopia. This condition causes the viewer to see objects at a distance clearly, while the objects close to the viewer are progressively burred. While this condition can occur for multiple reasons as well, a person typically has hyperopia if the focal point of the focused light entering the eye is formed behind the retina.
The axial length of the eye grows as children age. As young people begin their young adulthood years, the eye generally stops growing and the axial length of the eye becomes more permanent. Thus, if the growth of the eye's axial length can be controlled during a child's youth, myopia or hyperopia can be reduced or even eliminated in the child's adulthood years. What is needed is an apparatus, system, and method for controlling the growth of the eye's axial length during any stage of life where the axial length of the eye is capable of growing.